Telomeres & Telomerase

Higher organisms have linear chromosomes, and DNA polymerases are unable to replicate the ends of these chromosomes. Telomeres, repetitive DNA regions of hexanucleotide repeats, protect chromosomal ends from deterioration during DNA replication. Inhibition of telomere extension leads to short telomeres and premature aging-related diseases, whereas uncontrolled telomere lengthening promotes carcinogenesis. Telomerase (TERT), a reverse transcriptase, forms a complex with an RNA template and cofactors to extend telomeres. The shelterin protein complex then binds the 3' single-stranded end of telomeric DNA, protecting it from DNA damage responses. One protein, SLX4, forms a complex involved in DNA repair that includes proteins recently described in telomere regulation. However, many of the proteins that are known to be associated with telomeres have unknown functions. Research into telomeres often utilizes simpler model organisms, such as yeast, meaning that many mechanistic details have yet to be discovered or confirmed in mammalian systems. ...

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Higher organisms have linear chromosomes, and DNA polymerases are unable to replicate the ends of these chromosomes. Telomeres, repetitive DNA regions of hexanucleotide repeats, protect chromosomal ends from deterioration during DNA replication. Inhibition of telomere extension leads to short telomeres and premature aging-related diseases, whereas uncontrolled telomere lengthening promotes carcinogenesis. Telomerase (TERT), a reverse transcriptase, forms a complex with an RNA template and cofactors to extend telomeres. The shelterin protein complex then binds the 3' single-stranded end of telomeric DNA, protecting it from DNA damage responses. One protein, SLX4, forms a complex involved in DNA repair that includes proteins recently described in telomere regulation. However, many of the proteins that are known to be associated with telomeres have unknown functions. Research into telomeres often utilizes simpler model organisms, such as yeast, meaning that many mechanistic details have yet to be discovered or confirmed in mammalian systems.